In recent years, it is increasingly necessary to reduce the size of circuit patterns for high integration of a large-scale integrated circuit device (hereinafter, referred to as “LSI”) that can be achieved with semiconductors. As a result, reduction of the width of a line for wiring patterns constituting a circuit or reduction of the size of contact hole patterns (hereinafter, referred to as “contact patterns”) that connect between layered wirings formed with an insulating layer therebetween have become very important.
Hereinafter, reduction of the size of wiring patterns and contact patterns with a conventional light-exposure system will be described by using a positive resist process as an example. In a positive resist process, a line pattern refers to part of a resist film (resist pattern) which is not exposed with exposure light, i.e., part thereof which is left after development. A space pattern refers to part of a resist film which is exposed with exposure light, i.e., an opening portion which is formed by removing part of a resist film by development (resist-removed pattern). A contact pattern refers to a hole-like opening which is formed by removing part of a resist film by development and can be regarded as a small space pattern of the space patterns. When using a negative resist process instead of a positive resist process, the definition of the line pattern and the definition of the space pattern are replaced by each other.